The 12 days of GCHQ quizmas: test your brain power with these daily puzzles

Fuel cell generates power from human blood

A scientific advance could save patients the danger and stress of having to go through operations to replace the batteries in electronic implants.

A team at the University of British Columbia in Vancouver, Canada, has created a fuel cell that can generate power from human blood plasma, thereby removing the need to insert batteries into devices like pacemakers.

ADVERTISEMENT

New Scientist reports that the team has created microbial fuel cells, which are essentially yeast cells contained in a flexible capsule. These yeast cells generate energy by feeding on the glucose in human blood.

Researchers Mu Chiao and Chin-Pang-Billy Siu, who co-wrote the paper in the Journal of Microelectrical Systems, say that one fuel cell can produce around 40 nanowatts of power. To put this into perspective, an average wristwatch will produce about 1,000 nanowatts.

Mu said that the tiny amount of electricity generated will be enough to power some devices if a capacitor is used to store up energy, and suggested that the yeast could be genetically modified to increase its power output. The team is currently using Saccharomyces cerevisiae, a type of yeast used in baking and brewing. This is then contained with a 15 by 1.4mm silicone cell.

ADVERTISEMENT

To create a current, a chemical called methyl blue is being used to harness some of the electrons produced when the yeast metabolises sugar found in the blood and deliver them to the anode side of the cell. On the cathode side of the cell, hydrogen ions that diffuse out of the cell during this process combine with oxygen in the blood to produce water.

Dealing with other waste materials produced by the cell remains an obstacle, but Lars Angenent, who is researching microbial fuel cells at Cornell University, told New Scientist that he is optimistic about finding a solution. "I think people will figure this out," he said. "This is a first step."